1. Technical Field Text
This invention relates to medical devices and more particularly to devices which can be deployed by endovascular means into the vasculature of a patient.
2. Background
There exist endovascular stent grafts which can be deployed into the vasculature system so as to treat aortoiliac aneurysms. It is often necessary to produce stent grafts that have branches, the branches arranged to match anatomical branches in the vascular system.
Branched endovascular stent grafts for use in treating aortoiliac aneurysms require the insertion of a covered stent to bridge the gap between the endovascular graft and the internal iliac artery. A preferred method of introducing the covered stent is to insert the stent through the iliac/femoral artery on the contralateral side and guide the stent up and over to the ipsilateral side where it is deployed (the “up and over” approach). With some stent grafts, a fenestration or valve is provided in the wall of the stent graft to allow temporary access for a catheter to allow deployment of the covered stent through the iliac/femoral artery.
The above-described up and over access from the contralateral side is not ideal for all patients. Stent grafts having fenestrations or valves are difficult to design and manufacture for patients with short common iliacs because of the lack of room on the stent graft in the region of the common iliac. Furthermore, difficulties can arise in design of closing mechanisms for valved fenestrations.
It is an object of the present invention to provide an improved stent graft that ameliorates the aforementioned problem(s) or at least offers a useful choice
Throughout this specification, when discussing the application of this invention to the aorta or other blood vessels, the term “distal” with respect to a prosthesis is intended to refer to a location that is, or a portion of the prosthesis that when implanted is, further downstream with respect to blood flow; the term “distally” means in the direction of blood flow or further downstream. The term “proximal” is intended to refer to a location that is, or a portion of the prosthesis that when implanted is, further upstream with respect to blood flow; the term “proximally” means in the direction opposite to the direction of blood flow or further upstream.